Image Painting Board for Android,

Image Painting Board for Android,

This article focuses on the implementation of image drawing board for Android

Design Project Layout:

<RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android" xmlns: tools = "http://schemas.android.com/tools" android: layout_width = "match_parent" android: layout_height = "match_parent" android: paddingBottom = "@ dimen/activity_vertical_margin" android: paddingLeft = "@ dimen/plugin" android: paddingRight = "@ dimen/plugin" android: paddingTop = "@ dimen/plugin" tools: context = ". mainActivity "> <ImageView android: layout_above =" @ + id/bt "android: id =" @ + id/iv "android: layout_width =" fill_parent "android: layout_height = "fill_parent"/> <Button android: id = "@ + id/bt" android: layout_width = "fill_parent" android: layout_height = "wrap_content" android: layout_alignParentBottom = "true" android: onClick = "save" android: text = "save image"/> </RelativeLayout>

First, implement the drawing function:

Public class MainActivity extends Activity {private ImageView iv; private Bitmap baseBitmap; private Canvas canvas; private Paint paint; @ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); iv = (ImageView) findViewById (R. id. iv); paint = new Paint (); paint. setStrokeWidth (5); paint. setColor (Color. GREEN); // create a modifiable bitmap baseBitmap = Bitmap. createBitmap (320,360, Bitmap. config. ARGB_8888); System. out. println ("Image Width:" + iv. getWidth (); System. out. println ("Image Height:" + iv. getHeight (); canvas = new Canvas (baseBitmap); canvas. drawColor (Color. WHITE); // knows the trajectory of the user's finger moving on the screen iv. setOnTouchListener (new OnTouchListener () {// set the coordinate int startX; int startY; @ Override public boolean onTouch (View v, MotionEvent event) {switch (event. getAction () {case MotionEvent. ACTION_DOWN: // the first time the finger contacts the screen startX = (int) event. getX (); startY = (int) event. getY (); break; case MotionEvent. ACTION_MOVE: // slide int newX = (int) event with your finger on the screen. getX (); int newY = (int) event. getY (); canvas. drawLine (startX, startY, newX, newY, paint); // re-update the start position of the paint brush startX = (int) event. getX (); startY = (int) event. getY (); iv. setImageBitmap (baseBitmap); break; case MotionEvent. ACTION_UP: // finger exit screen break; default: break;} return true ;}});} public void save (View view ){}}

The following describes how to save an image:

Public void save (View view) {try {File file = new File (Environment. getExternalStorageDirectory (), System. currentTimeMillis () + ". jpg "); FileOutputStream stream = new FileOutputStream (file); baseBitmap. compress (CompressFormat. JPEG, 100, stream); stream. close (); Toast. makeText (this, "saved image succeeded", 1 ). show (); // simulate a Message notification system where the SD card is remounted with Intent intent = new Intent (); intent. setAction (intent. ACTION_MEDIA_MOUNTED); intent. setData (Uri. fromFile (Environment. getExternalStorageDirectory (); sendBroadcast (intent);} catch (Exception e) {Toast. makeText (this, "failed to save the image", 1 ). show (); e. printStackTrace ();}}